Configuration for knife sharpeners that rotationally stabilizes them and knife sharpeners that conform to it

ABSTRACT

My invention is a configuration or layout for the pull-through type of knife sharpener that rotationally-stabilizes them during use as well as the sharpeners that incorporate this improvement. The improvement applies to the portable counter-top sharpeners that were primarily designed for sharpening knives. These sharpeners consist of a base with a set of blade-cutters. The blade-cutters are comprised of opposing sharpening members that form a V-notch that a knife blade is placed into and drawn through. The configuration is used to stabilize these sharpeners from the tendency to rotate both longitudinally and laterally while in use. The configuration includes three main features. The base is lengthened when compared to sharpeners of their type and the cutters are mounted on the front end on one side of the base. There is a stabilization-zone which holds a position relative to the base. Part of the handle-area is located in this stabilization zone.

BACKGROUND OF THE INVENTION

1. Field of The Invention

My invention directly relates to the pull-through family of knifesharpeners. These are manual knife sharpeners that are held stable to acounter-top by hand as a knife blade is pulled across generally opposingcutting elements that removes metal from both sides of the knifes edge.

2. Description of the Prior Art

Late in the 19th century, the rock, located near the kitchen outdoorexit, was the dominant sharpening device. In the early 20th century, thepull-through knife sharpener became the predominant kitchen sharpener.It's reign lasted until the late twentieth century. Many of thepull-through designs were designed to simply hold the sharpener up inthe air with one hand while pulling the knife's edge through with theother.

In the last two decades, metallurgical science has evolved andprosperity has increased. As time has gone by, knife blades startedgetting harder and tougher. High carbon steels were alloyed with nickel,chromium and molybdenum to make harder, tougher and primarily stainlesssteels. The pull-through sharpeners began failing to do the job. Knifesharpeners first began evolving by simply replacing the blade-cutterswith harder materials. Higher grades of tool steel as well as tungstencarbide (a harder metal) were employed.

The new materials only solved half of the new challenges. The alloysthat gave the knives stain resistance also increased the toughness ofthe blades ten-fold. The cutting elements in the sharpeners were cuttingstainless steel instead of plain high carbon steel. The difference ofcutting high carbon steel to stainless steel can be compared towhittling a pine stick and whittling hardened bubble gum. The stainlessalloys made steel tougher. You have to press down several times as hardon the knife blade as well pull the knife several times as hard get thejob done.

Suddenly, it required considerable strength to stabilize the sharpenerby hand. The sharpener wants to twist in your hand both longitudinallyand laterally. (FIGS. 9 through 12 show the coordinate definitions ofthese directions.)

Old designs became inadequate to do the job.

U.S. Pat. No. 51,285 from 1865 in FIG. 1 (front view) and FIG. 2 (sideview)

This is the oldest on-line patent for a dual disk pull-throughsharpener. The patent is dated 1865. This was almost a novelty item, acombination serving-fork and sharpener. That indicates that the“pull-through” design approach was already old at the time this patentwas applied for.

Observation of the design shows the long distance of the fork handle tothe blade-cutter located between the fork's prongs. This design couldn'twork today. You wouldn't be able to hold the fork rigid enough, whileheld in mid-air, to prevent movement of the fork while pulling a knife'sedge through.

U.S. Pat. No. 431,887 from 1890 in FIG. 3 (Perspective view) and 4 (topview)

The sharpener in this patent is one of few that were made with a longbase. 95% were made with a base under on 1 inch. The reason this one hada long base was not one of stabilizing rotation. To sharpen, you pulledthe knife past the cutters. This sharpener was not designed to slideover a counter-top's edge. Once the blade's tip moved past theblade-cutter, the blade slapped the base, opposed to hitting thecounter-top. The location of the blade-cutter across from thehandle-area failed to provide much lateral rotation stabilization;however, there was plenty of stability to accommodate knife metallurgyduring that period.

U.S. Pat. No. 1,762,698 from 1928 in FIG. 5 (Top view), FIG. 6 (frontview) and FIG. 7 (bottom view)

This sharpener family had the longest and largest successful productionrun of any sharpener. It literally dominated the market from around the1920's and 1930's through the 60's. I saw one for sale in the 1990,which was well beyond the useful life of the design. The reason it wasstill a marketable device was because of its long successful history.People were still willing to take a chance on it. It has two columns ofcutter discs that run the full length of the compact, short base with ahandle-area attached directly to the side of the blade-cutter.

BRIEF SUMMARY OF THE INVENTION

There is a need for a low-cost, inexpensive, counter-top, pull-throughsharpener that has been rotationally-stabilized.Rotationally-stabilizing the old designs will enable the pull-throughtechnology to be useful with today's high alloy knives. My invention isa configuration or layout for the pull-through type of knife sharpenersthat rotationally-stabilizes them. My invention also includes sharpenersthat conform to this improvement.

The sharpeners are the pull-through type. They are designed to rest on acounter-top and held secure by one hand while the blade of a knife ispulled past the V-notch blade-cutter with the other.

The improved configuration deals with the general component layout ofthe sharpener as well as the base design and handle-area location. Theblade-cutter is located on the front end of the sharpener's base.

There is a stabilization-zone located relative to the base. By locatingthe handle-area within this zone, the tendency of the sharpener torotate—can be neutralized.

This invention significantly improves the pull-through type of sharpenerand renews it as a viable option.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE INVENTION

FIG. 1 is a front view of a prior art serving fork sharpener.

FIG. 2 is a side view of a prior art serving fork sharpener.

FIG. 3 is a perspective view of a prior art long-based sharpener.

FIG. 4 is a top view of a prior art long-based sharpener.

FIG. 5 is a top view of the most popular sharpener of prior art.

FIG. 6 is a side view of the most popular sharpener of prior art.

FIG. 7 is a bottom view of the most popular sharpener of prior art.

FIG., 8A through FIG. 21 are of the present invention

FIG. 8-A through 8-F are perspective views of several versions of thisinvention's rotationally-stable sharpeners.

FIG. 9 is a perspective view of an “L” based sharpener and theorientation of different views.

FIG. 10 is a top view showing lateral rotation direction.

FIG. 11 is a front view showing clockwise and counter-clockwise rotationdirection.

FIG. 12 is a side view showing longitudinal rotation.

FIG. 13 is a top view of a sharpener.

FIG. 14 is a side view of a sharpener.

FIG. 15 is a perspective view of a sharpener over the edge of acounter-top.

FIG. 16 is a perspective view of a sharpener with a knife in thebeginning position

FIG. 17 is a perspective view of a sharpener with a knife in endingposition.

FIG. 18 is a side view of a sharpener in use.

FIG. 19 is a side view showing longitudinal rotational forces beingapplied to a sharpener.

FIG. 20 is a long sharpener showing a zone where longitudinal rotationcan be neutralized.

FIG. 21 is a top view of a sharpener that is being stabilizedlongitudinally by hand.

FIG. 22 shows the most popular sharpener's shape of prior art rotatinglaterally while in use.

FIG. 23 through FIG. 39 are of the present invention.

FIG. 23 shows the location where lateral and longitudinal rotation canbe cancelled.

FIG. 24 shows the blade-path area of the base.

FIG. 25 shows the stabilization zone's location relative to theblade-cutter.

FIG. 26 is a perspective view of an “L” shaped sharpener.

FIG. 27 is a perspective view of a folding “L” shaped sharpener unfoldedfor a right-handed person.

FIG. 28 is a perspective view of a folding “L” shaped sharpener folded.

FIG. 29 is a perspective view of a folding “L” shaped sharpener unfoldedfor a left-handed person.

FIG. 30 is a perspective view of a “T” shaped sharpener.

FIG. 31 is a perspective view of a rectilinear shaped sharpener.

FIG. 32 is a perspective view of a rectilinear shaped sharpener with asafety wall.

FIG. 33 is a perspective view of a rectilinear shaped sharpener with afront alignment tab.

FIG. 34 is a perspective view of a rectilinear shaped sharpener that hasa sculpted handle-area that fits the operator's hand.

FIG. 35 is a perspective view of a sharpener that has a verticalhandle-area.

FIG. 36 shows a V-bar blade-cutter.

FIG. 37 shows a one-piece V-notch blade-cutter.

FIG. 38 is an exploded perspective view of multiple disc blade-cutter.

FIG. 39 is a front view of a multiple disk blade-cutter.

DETAILED DESCRIPTION

Orientation

My invention is a configuration for knife sharpeners thatrotationally-stabilizes them as well as many optional knife sharpenersthat conform to the configuration. They will sharpen other things aswell. FIGS. 8-A through 8-F give an overview of some of the differentshapes the sharpener may take. There are several more listed in thedocument and many other shapes are possible within the configuration.FIGS. 9 through 12 show the orientation terminology used in thisdocument. All descriptions are of the sharpener or components sitting infront of you and ready for use. In FIG. 9 there are arrows labeled frontview. The view is from the perspective of a person looking in thedirection of the arrow at the sharpener. FIG. 11 is the front view, etc.All of the descriptions of the sharpeners are with a sharpenerpositioned on a table in front of you and oriented for use. Width is thedirection between your left and right. Thickness is from top to bottom.Length is from front to back.

Definition of Terms

Counter-top—Refers to the tops of counters, tables or any suitableworking surface.

Rotationally-stabilized—Old designs were stable on theclockwise/counterclockwise axes. “Rotationally-stabilized” or“rotationally-stable” refers to stability of the additional longitudinaland lateral axis of rotation.

Hand-stabilized refers to a method of securing the sharpener to thecounter-top. It means that there is a handle-area allocated for thatuse. There can also be additional means for a more permanent mount suchas screw holes.

A long base—Refers to the extra long base length of these sharpenerswhen compared to other sharpeners of this type. The sharpener base canbe from 2” to 31” long.

Blade-cutter—The thing that actually removes metal from the knife blade.It is made from generally opposing cutting elements that intersect andform a V-notch. The V-notch types include cutter-bar, multiple disk orfile types.

V-notch—The individual cutting elements are positioned in relation toeach other and oriented on the base in such a way that the element'sintersection looks like a generally upright “V” as seen by the operator.

Cutter-vertex—This is a location on a blade-cutter. It is theintersection of the opposing cutting elements

Blade-path area—It is the area of the base that the knife passes over.That's the “comfortable” area allowing for misalignment. It includesspace behind the actual area the blade passes over. It runs from thefront of the base to the rear of the base.

Handle-area—area of the base that is/was allocated by the designer forholding the sharpener steady on a counter top by hand during use.Stabilization-zone—Zone related to the base where 2 axes of rotation canbe neutralized if a handle-area is located within.

“L” shaped sharpener—One can be seen in FIG. 26.

“T” shaped sharpener—One can be seen in FIG. 30.

A rectilinear sharpener—One can be seen in FIG. 31.

Vertical safety wall—It is a wall between the handle-area and theblade-path area. One can be seen in FIG. 32.

Front alignment tab—One can be seen in FIG. 33.

Sculpted handle-area—One can be seen in FIG. 34.

A vertical handle-area—One can be seen in FIG. 35.

High-traction surface—This helps secure the sharpener to a counter-top.In the preferred embodiment, silicone rubber would be used; however,there are many coatings that would work.

There Are Three Key Elements in the Configuration:

1. The blade-cutter is located on the front of a long base.

2. There is a stabilization-zone located behind the blade-cutter.

3. The sharpener sits on a counter-top and is held steady by hand duringuse.

The area of the base that's used as a handle is called the handle-area.To prevent the sharpener from rotating, some of this handle-area needsto be located in the stabilization-zone.

The clearest way to define the configuration is to describe sharpenersthat conform to it. The following describes a rotationally-stabilizedsharpener and its design limits.

The Base Details

As can be seen in FIGS. 13 and 14, there are two main components of asharpener (S). There is the blade-cutter (2) that removes metal from theknife blade and there is the base (1).

FIG. 15 shows the normal position of the sharpener (S) positioned foruse on a counter-top (4). The sharpener is placed a little past the edgeof the counter to prevent cutting it. FIGS. 16 and 17 illustrate thebeginning and ending positions of a knife (3) being pulled-through thesharpener.

FIG. 18 is a side view of the sharpener in use. The knife (3) is tilteddown a little, pressed down and pulled back. This would cause afree-standing sharpener to rotate longitudinally and fall off of thecounter-top as can be seen in FIG. 19.

In FIG. 20 you see the sharpener with a rectangle (Z) identified on thebase. If you held the sharpener with your hand (5) in the zoned area (Z)as seen in FIG. 21. Longitudinal rotation would be neutralized.

FIG. 22 is a top view of a wide sharpener on a counter (4) with a smallzone (T) identified on the far left side of a sharpener. If one were tohold the sharpener (S) with a finger-tip located within the hatched area“T”, it would try to rotate laterally along the arc labeled “R”. If youheld a sharpener in the stabilization-zone (Z) as show in FIG. 23, therewould be no lateral rotation. By the way, notice the sharpener'sfootprint in this FIG. 22. This is the footprint of the most widelymanufactured model of prior art listed in the “Description of the PriorArt” section.

The base has two general areas. There is the blade-path (BP) area andthe handle-area (HA). FIG. 24 shows the knife (3) positioned over theblade-path (BP) portion of the sharpener's base. The blade-path area isthe area on the base that the knife passes over. That's the“comfortable” area allowing for misalignment. It can include spacebehind the actual area the blade passes over. It runs from the front ofthe base to the rear of the base.

Stabilization-Zone (Z)

In FIG. 25 you will see a V-notch blade-cutter and a box behind it. Thebox drawn with a dashed line represents the stabilization-zone. Thestabilization zone begins a couple of inches behind the blade-cutter. It(Z) extends to the rear of the base. The blade cutter has a line labeled“CV” running through it. This line represents the intersection of thetwo cutting elements. It is called the cutter-vertex. The width of thestabilization zone is about two and one-half inches to either side ofthe cutter-vertex. The zone begins at the bottom of the base and extendsupward three inches.

The handle-area (HA) will be attached to the blade-path area (BP) withinthe stabilization zone (Z) on all sharpeners that conform to therotationally stabilized configuration of the present invention.

FIGS. 26 through 35 show some, but not all, of the basic shapes thesesharpeners can take. Each sharpener has the handle area (HA) andblade-path (BP) areas of the base (1) identified.

FIG. 26 is an “L” shaped sharpener. This is the preferred embodiment.

In FIGS. 27 through 29 show a convertible feature. The handle-area ispositionable in relation to the blade-path. It can swap between the leftand right side, or just switch between the left side and straight. Thismight be convenient for storage. One way to do this would be a pivotassembly or hinge. FIGS. 27 through 29 are of an “L” shape with a pivot(5) that allows folding for storage or converting for left and righthanded people.

FIG. 27 is unfolded for a right-handed person. FIG. 28 is folded andFIG. 29 shows it unfolded for a left-handed person. A pivot would alsoallow for a neutral position, this would make the sharpeners basestraight for storage.

A pivot or hinge are two means for accomplishing this. Others wouldinclude a puzzle-piece approach or even a handle-area that slidesthrough the blade-path portion of the base.

FIG. 30 is a “T” shaped sharpener.

FIG. 31 has a rectangular shape.

FIG. 32 is a rectangular shape with a safety wall (7) to preventaccidents.

FIG. 33 is a rectangular shape with a tab (6) in the front that butts upto a counter-top's edge.

FIG. 34 shows a general rectangle shape with a sculpted handle-area (9).

In FIG. 35, the vertical handle-area (HA) is located in thestabilization-zone (Z).

Blade-Cutter (2)

The blade-cutter (2) is the tool that actually removes material from theknife blade. Each blade-cutter type that is supported has a V-notch thatthe knife is drawn through. The cutters are positioned such that theV-notch is square to the base and makes a “V” as seen by the operator.The sharpener will accommodate different V-notch blade-cutter types. Theblade-cutter elements are made out of tungsten carbide in the preferredembodiment. These blade-cutter types include (but are not limited to),the V-bar type as shown in FIG. 36, the multiple disk, as seen in FIG.38, and file types.

Detailed Description of Cutter Types Supported:

V-Bar Type:

The blade-cutter in FIG. 36 is composed of a left cutter bar (10) and aright cutter bar (11), which are positioned together to form a “V”. InFIG. 36, the cutter-bars are square. In the preferred embodiment, theyare rectangular and wider than long.

A one-piece V-notch blade-cutter is shown in FIG. 37.

Multiple Disk

The blade-cutter shown in FIGS. 38 and 39 is called the multiple disk.There are two rows of disks (8) mounted to a base (9). Sometimes thereare multiple disks per row.

V-File

The V-bar design shown in FIG. 36 is the layout for the V-file type ofblade-cutter. Flat files or round files would be substituted for thecutter bars (10 and 11).

Other Possible Components

Another aid is a high-traction surface on the bottom of the base. Thishelps secure the sharpener to a counter-top. In the preferredembodiment, silicone rubber would be used; however, there are manycoatings that would work.

Method of Operation

In FIG. 15 you can see the sharpener (S) positioned upon a counter-top(4) with the blade-cutter (2) upward and the edge of the sharpenerhanging a little past the edge of the counter-top (4). The left hand isused to secure the sharpener to the counter-top (4) as can be seen inFIG. 21. A knife's (3) blade is laid in the blade-cutter's (2) V-notch,next to the handle or hilt of the knife (3) as seen in FIG. 16. As thesharpener is secured with the left hand, the right hand presses theblade downwards as the knife (3) is drawn back to the ending position asshown in FIG. 17. This is repeated until the knife is sharp. It normallytakes one to two repetitions.

1. A configuration for a hand-stabilized, pull-through, counter-top,knife sharpener that makes the sharpener rotationally-stable,comprising: a blade-cutter having generally opposing cutting elements,the cutting elements forming a transverse generally upright V-notch thatopens upward with a cutter-vertex at the intersection of the cuttingelements; a base comprising: a front portion and an opposing rearportion; a front extent and a rear extent; a left side and an opposingright side; a bottom surface and a top surface; a blade-path area on thebase extending from the front extent to the rear extent; and ahandle-area for securing the sharpener relative to the counter-top; anda stabilization-zone located relative to the base such that thesharpener can be stabilized on the longitudinal and lateral axes of thesharpener when the handle-area resides within the stabilization-zone andthe handle-area is held by the user; wherein the blade-cutter is mountedon the front portion of the base within the blade-path area; wherein thewidth of the stabilization-zone extends two and one-half inches toeither side of the cutter-vertex, the height of the stabilization-zonebegins at the bottom surface and extends upward at least three inches,and the length of the stabilization-zone begins at least two inchesbehind the blade-cutter and extends to the rear extent of the base; andwherein the handle-area is located at least partially within thestabilization-zone.
 2. A hand-stabilized, pull-through, counter-top,sharpener that is rotationally-stable, comprising: a blade-cutter havinggenerally opposing cutting elements, the cutting elements forming atransverse generally upright V-notch that opens upward with acutter-vertex at the intersection of the cutting elements; a basecomprising: a front portion and an opposing rear portion; a front extentand a rear extent; a left side and an opposing right side; a bottomsurface and a top surface; a blade-path area on the base extending fromthe front extent to the rear extent; and a handle-area for securing thesharpener relative to the counter-top; and a stabilization-zone locatedrelative to the base such that the sharpener can be stabilized on thelongitudinal and lateral axes of the sharpener when the handle-arearesides within the stabilization-zone and the handle-area is held by theuser; wherein the blade-cutter is mounted on the front portion of thebase within the blade-path area; wherein the width of thestabilization-zone extends two and one-half inches to either side of thecutter-vertex, the height of the stabilization-zone begins at the bottomsurface and extends upward at least three inches, and the length of thestabilization-zone begins at least two inches behind the blade-cutterand extends to the rear extent of the base; and wherein the handle-areais located at least partially within the stabilization-zone.
 3. Thesharpener of claim 2, wherein the stabilization-zone optionally beginsat least two and one-half inches rearward of the cutters and extends tothe rear extent of the base.
 4. The sharpener of claim 2, wherein thestabilization-zone optionally begins at least three inches rearward ofthe cutters and extends to the rear extent of the base.
 5. The sharpenerof claim 2, wherein the stabilization-zone optionally begins at leastthree and one-half inches rearward of the cutters and extends to therear extent of the base.
 6. The sharpener of claim 2, wherein thestabilization-zone optionally begins at least four inches rearward ofthe cutters and extends to the rear extent of the base.
 7. The sharpenerof claim 2, wherein the stabilization-zone optionally begins at leastfour and one-half inches rearward of the cutters and extends to the rearextent of the base
 8. The sharpener of claim 2, wherein thestabilization-zone optionally begins at least five inches rearward ofthe cutters and extends to the rear extent of the base
 9. The sharpenerof claim 2, wherein the stabilization-zone optionally begins at leastfive and one-half inches rearward of the cutters and extends to the rearextent of the base
 10. The sharpener of claim 2, wherein the base is “L”shaped.
 11. The sharpener of claim 2, wherein the handle-area containsmeans for adjusting the handle-area between the left side of the baseand the right side of the base.
 12. The sharpener of claim 2, whereinthe handle-area contains means for adjusting the handle-area between theleft side of the base and a neutral position.
 13. The sharpener of claim2, wherein the base is “T” shaped.
 14. The sharpener of claim 2, whereinthe base is rectilinear.
 15. The sharpener of claim 2, furthercomprising a vertical safety wall coupled to the base that extendslongitudinally between the handle-area and the blade-path area.
 16. Thesharpener of claim 2, further comprising a front alignment tab foraligning the sharpener to with the edge of the counter-top.
 17. Thesharpener of claim 2, wherein the handle-area is sculpted to fit thehand.
 18. The sharpener of claim 2, wherein the handle-area ascendsvertically and at least partially within the stabilization-zone.
 19. Thesharpener of claim 2, wherein the blade-cutter is selected from thegroup consisting of V-bar, multiple disc, and V-file.
 20. The sharpenerof claim 2, wherein the base further comprises a high-traction surfacefor reducing movement of the sharpener relative to the working surface.